1. Technical Field
The present invention relates in general to controlling aircraft exhaust and, in particular, to an improved system, method, and apparatus for vectoring the exhaust plume from a nozzle with external actuation relative to the nozzle.
2. Description of the Related Art
Higher demands for air vehicle performance and affordability directly impact exhaust system requirements. Future exhaust systems must provide a high thrust coefficient, thrust vectoring with quick response, compatibility with engine operation, light weight, and low cost. Mechanical vectoring systems can achieve good thrust and vectoring performance by actuating large surfaces that comprise part of the nozzle. However, these nozzles are heavy, complex and expensive.
Fluidic nozzle vectoring systems are significantly lighter and simpler than mechanical vectoring systems due to the use of integral fluid injectors for thrust vector control. This permits the elimination of most moving parts, resulting in reduced weight, complexity and cost. However, conventional fluidic vectoring systems sometimes sacrifice peak thrust performance in order to obtain a desired level of vectoring performance. This results from compromising nozzle internal shaping and bleeding high pressure flow from the engine to supply the fluid injectors. For example, the desired vectoring capability may require a larger nozzle exit area than that required for peak thrust performance, resulting in nozzle thrust loss. Also, bleeding a portion of the engine airflow to provide a source for the fluid injectors incurs engine performance penalties. Thus, although both mechanical and fluidic vectoring designs are workable, an improved design would be desirable.